JP2628344B2 - Golf club head - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club head, and more particularly, to an improvement in a wood club head comprising an outer shell of fiber reinforced plastic.

[Conventional technology]

In general, a club head body having an outer shell formed of fiber reinforced plastic as a material, particularly a wood golf club head 1 having an outer shell formed of carbon fiber reinforced plastic (CFRP) is shown in FIG. 2, for example. As described above, the core 2 is made of a syntactic foam or the like, the outer shell 3 is formed of carbon fiber reinforced plastic, and a metal sole plate 4 is integrally mounted on the sole portion.

The carbon fiber reinforced plastic constituting the outer shell 3 uses an unsaturated polyester resin, a vinyl ester resin, an epoxy resin, or the like as a matrix resin.

[Problems to be solved by the invention]

However, the club head main body 1a formed of the matrix resin and the fibers may have uneven waving phenomena on the surface of the molded product due to the difference in thermal shrinkage between the resin and the fibers at the time of thermosetting of the resin. Internal cracks in the thick part,
There is also a problem that a gap is easily formed between the insert (sole plate 4) that does not shrink and the outer shell 3 made of carbon fiber reinforced plastic that causes heat shrink. In particular, when the SMC (sheet molding compound) having a long reinforcing fiber was used as a material, it was particularly remarkable.

For this reason, conventionally, after molding the club head body 1a,
After polishing and smoothing the uneven part of the surface, the surface must be painted, and in the area where gaps have occurred, the filler must be buried and the filling process must be done after filling Therefore, it takes a lot of trouble and time,
There was a problem that the cost was further increased.

[Object of the invention]

The present invention has been devised in view of such a conventional problem, and does not cause a waving phenomenon such as unevenness on the surface of the outer shell after molding of the club head, without generating cracks, gaps and the like. An object of the present invention is to provide a golf club head that can form a product surface smoothly, can omit finishing work after molding, and can improve the durability of a club head body and a face portion. It is assumed that.

[Means for solving the problem]

The present invention has been devised to achieve the above-mentioned object. As shown in FIG. 1, the structure of the present invention is such that a golf club head main body 11 is formed by using an outer peripheral surface of a core body 12 made of fiber reinforced plastic as a material. It is covered with a shell 13 to form an integral structure, and a sole plate 14 has a plurality of anchor pins on the sole part.
Attached via 15.

Reference numeral 16 denotes a metal cylinder mounted on the back side of the sole plate 14 and having both weight adjustment and impact resistance.

In the present invention, the fiber-reinforced plastic constituting the outer shell 13 is formed of a synthetic resin for a matrix in which a modified hydrogenated styrene / butadiene / styrene copolymer resin is blended, and a main component of the synthetic resin for the matrix is as follows. A vinyl ester resin or an epoxy resin, an unsaturated polyester resin, and a modified hydrogenated styrene / butadiene / styrene copolymer resin in an amount of 2 to 12 parts by weight based on 100 parts by weight of the matrix synthetic resin. It is composed.

The core 12 may be composed of 120 parts by weight of a vinyl ester resin (Lipoxy M-7020: Showa Polymer Co., Ltd.),
1.5 parts by weight and 0.5 parts by weight of hardeners A and B (Showa Kogaku Co., Ltd.) are mixed respectively, and 100 parts by weight of this mixture is mixed with 28.7 parts by weight of glassy micro hollow spheres A16 / 500 (3M Corporation). Stir and mix to obtain a paste-like uncured syntactic foam composition, fill this into a golf club head core molding die, heat and cure in an oven to obtain a syntactic foam core having a specific gravity of 0.45. It is a body.

As a method of manufacturing the golf club head main body 11 configured as described above, for example, the core 12 and the modified hydrogenated styrene / butadiene / styrene copolymer resin are added in an amount of 2 parts by weight based on 100 parts by weight of the matrix synthetic resin. Parts to 12 parts by weight of fiber reinforced plastics such as SMC (sheet molding compound) and sole plate 14
Are inserted together into a club head compression molding die (not shown), and are heated, pressed and cured to integrally form the club head.

〔The invention's effect〕

According to the present invention, the fiber-reinforced plastic outer shell of the golf club head body is
Since it is made of a synthetic resin for a matrix in which a butadiene / styrene copolymer resin is blended, the following excellent effects can be obtained.

(A). Since the surface of the formed club head is smooth, it is possible to greatly reduce the smooth finishing work after the molding as in the related art, and it is possible to significantly improve the workability.

(B). When the club head body is integrally molded, the gap between the carbon fiber reinforced plastic and the sole plate is reduced, so that a sealing step after molding can be omitted, and workability can be improved.

(C). Since internal cracks do not enter the thick portion of the outer shell made of carbon fiber reinforced plastic, the durability of the club head body can be improved.

(D). Since the outer shell is formed of a synthetic resin for a matrix containing a modified hydrogenated styrene / butadiene / styrene copolymer resin, the impact resistance is improved and the durability of the head face portion is improved.

〔Example〕

Hereinafter, examples of the example of the mixing of the matrix resin will be described.

"Example of blending with vinyl ester resin" Bisphenol-based epoxy resin (epoxy equivalent 475) 1
A prepolymer obtained by adding 7 parts of acrylic acid and 20 parts of methyltetrahydrophthalic anhydride to 00 parts and reacting in advance
25 parts of calcium carbonate, 100 parts of modified styrene / butadiene / styrene copolymer resin dissolved in styrene monomer (10 parts as resin), 2 parts of dicumyl peroxide as curing agent 1.5 parts of zinc stearate And 3 parts of magnesium hydroxide are mixed well, and the length is 25mm ~
A fiber reinforced plastic outer shell obtained by adding 50 mm fiber to the matrix resin 100 within a processable range is manufactured.

Table 1 below shows the results of experiments on the variables of the respective compounding amounts.
Shown in

"Examples of formulation into unsaturated polyester" Ethanol and phthalic anhydride are equimolarly mixed,
To 100 parts of a compound obtained by adding 30 parts of a styrene monomer to 100 parts of an unsaturated polyester obtained by reacting this with propylene glycol, 3.0 parts of benzoyl peroxide, 30 parts of calcium carbonate, 30 parts of zinc stearate, 1.0 part of water 55 parts of carbon cut fiber were mixed with a compound obtained by adding 1.5 parts of magnesium oxide and a modified amount of a modified hydrogenated SBS resin dissolved in a styrene monomer, followed by heating and pressing to form a fiber-reinforced plastic outer shell.

 Table 2 shows the results.

"Example of Formulation in Epoxy Resin" The results of adding a modified hydrogenated SBS resin for the purpose of toughening and smoothness of the epoxy resin are shown in Table 3 below.

Since this resin is not compatible with the epoxy resin as it is, it is mixed with the epoxy resin by heating, or the modified hydrogenated SBS resin is dissolved in phenyl glycidyl ether, styrene oxide, cresyl glycidyl ether, etc. Used.

[Conclusion] As can be seen in the above examples, by adding a modified hydrogenated SBS resin, vinyl esters, unsaturated polyesters and the like having a large shrinkage ratio upon curing have such a reactivity. The presence of a high molecular weight SBS block copolymer significantly reduces the degree of shrinkage, and creates a wavy phenomenon due to shrinkage, a toughness due to fine dispersion of the polymer, or a blister structure due to polymerization such as styrene. Is more effective in increasing the toughness.

Of course, the surface smoothness after molding is high because of the thermoplastic property and the small curing shrinkage.

The epoxy resin system has less curing shrinkage than the other two resins, but by adding this modified hydrogenated SBS resin, the curing shrinkage is further reduced, and the compatibility and reactivity with the epoxy resin are combined, A stronger improvement in impact resistance is observed.

In terms of the amount, the effect appears from about 2 parts by weight to 100 parts by weight of each resin, the effect is the most effective from about 8 parts by weight to about 10 parts by weight, and the effect is more than 12 parts by weight, There is not a remarkable difference, when saturation is reached, or when the amount is further increased, the amount of the monomer in the solution becomes relatively large, and the properties of the original resin are lost, and it becomes brittle, and it becomes difficult to process The above drawback also occurs. Therefore, it is preferable to use about 2 to 12 parts by weight per 100 parts by weight of each resin.

[Brief description of the drawings]

FIG. 1 is a sectional view of a wood club head body embodying the present invention, and FIG. 2 is a sectional view of a general wood club head body. 11 ... golf club head body, 12 ... core, 13 ... outer shell, 14 ... sole plate.

Claims (3)

(57) [Claims] 1. A golf club head comprising a golf club head body comprising a fiber reinforced plastic outer shell, wherein the golf club head body has a fiber reinforced plastic outer shell made of a modified hydrogenated styrene / butadiene / styrene. A golf club head formed of a synthetic resin for a matrix containing a polymer resin. 2. A main component of a synthetic resin for a matrix,
The golf club head according to claim 1, wherein the golf club head is a vinyl ester resin, an epoxy resin, or an unsaturated polyester resin. 3. The modified hydrogenated styrene / butadiene / styrene copolymer resin is mixed with the matrix synthetic resin 100.
2. The golf club head according to claim 1, wherein 2 to 12 parts by weight is blended with respect to part by weight.